Leader pin for die sets



R. C. DANLY LEADER PIN FOR DIE SETS Dec. 29 1925.

FiEd May 2 1924 III! illill fm/emior'x Rosa-R C,DA N1. Y

Patented Dec. 29, 1925.

"UNITED STATES 3033B: 0. DANLY, or CHICAGO, ILLINOIS, ASSIGNOR. 'ro ANLYI new 51mmwas, me, or CHICAGO, ILLINOIS, A coarona'rron orILLINoIs.

. V 1,568,017 P TE T/(OFF LEADER rm roa DIE sa'rs.

ii i ucauon and May 2, 1924'. Serial in. 710,571.

I To all whom it may concern.

Be it known that I, ROBERT C. D tNLY, a citizen of the United States of Amerlca, and a resident of Chicago, in the county of Cook 7 and State of Illinois, have invented a certain new and useful Improvement in Leader Pins for Die Sets, of which the following is a specification.

This invention relates to means for securing in place the leader pins which form the guiding means between the movable and stationary members of standard die sets of punching and forming presses, and the present improvement has for its objects:

To provide a structural formation and association of parts whereby a leader pin is firmly secured in a member of a die set in a readily removable manner so as to permit of repair, refinishing, etc., of said member, and a subsequent ready and substantial reassembly of the parts.

To provide means whereby an effective lubrication of the surface of the leader pin is attained in a ready and constant manner,

' die set to which the all as will hereinafter more fully appear.

In the accompanying drawing Fig. 1, is a perspective view of a standard present invention is ap lied.

ig. 2, is a sectional elevation on l1ne 22, Fig. 1.

Figure 3, is a detail horizontal sectlon on line 3-3, Fig. 2'.

Fi 4, is a detail sectional elevation of a mo cation.

Fi 5, is a bottom view of same.

L' e reference numerals indicate like parts in the several views.

The standard die set shown in the drawing as illustrative of the present invention, comprises a lower stationary member 1 adapted to be firmly clamped on the bed of a unching or forming press, and a movable member 2 having shank 3 for o erative connection with the reciprocating ead of the press. The two members 1 and 2, being accurately guided in their relative movement by a plurality of leader pins 4, usually 4 is formed with a strai htcylindrical-perimeter from end to en with a diameter equal to that of the receiving orifice therefor in the stationary member 1, say within onethousand of an inch, and so that the pin will have an accurate fit in said orifice. In the preferred construction shown in Figs. 1, 2 and 3 the leader pin 4 is formed with a centerbore or passage 5 extending from end to end of the pin, with thelower part of said as bore or orifice formed with a conical-coun= terbore 6, the taper of which is quite small or minute, ordinarily a one degree taper, for

y the reception of the hereinafter described expansion plug 7. In connection with the counterbore 6, the lower end of the leader pin 1s formed with one or more radical slits 8 to permit an expansion of such lower end of the leader pin in the final assembly of the die set parts.

The expander plug or wedge 7 above referred to, is of a very small or minute tapering form corresponding to the tapering end portion 6 of the bore of the leader pin, a ta er of one degree being found to afford e ective action in the present improvement. The lug or wedge 7 is preferably of a circu ar form in cross-section, as shown in Fig. 2, the scope of this part of the present invention, however, embraces the formation of the plug or. wedge 7' of a rectangular form in cross section as shown in Figs. 4 and 5.

When either type of the plug or wedge is driven into the end of the leader pin, a slight but very powerful expansion is attainedof the cylindrical lower portion of the leader pin 4 in the cylindrical receiving orifice of the stationary die set member 2, with a resulting stron nection or freezing o the parts together. In attaining a disassembly of the parts an ordinary drive pin is introduced through the central bore 5 of the leader pin to act against the upper end of the plug or wedge 7 and drive the same out of its engagement.

A further and important function of the aforesaid central bore 5 of a leader pin, is to provide a receiving chamber for a wick 9 saturated with a fluid lubricant, which is adapted to flow in a gradual manner through radlal orifices 10 into circular grooves 11, in the periphery of the leader pin, and thence to the guiding surface of the same.

Having thus fully described my invention and effective concentral channel aforesaid, so that when driven into place the plug will expand the attaching end of the leader pin into fixed engagement in said cylindrical orifice, and

a companion set member having sliding engagement with said leader pin.

2. In a die set for punching and forming )resses, the combination of a set member lormed with a cylindrical orifice, a leader pin cylindrical throughout to accurately fit said orifice and formed with a central bore extending the entire length of the pin, one end of said bore being formed with a conical counterbore of aminute taper, said pin end being slitted radially, a conical plug of a complementary tapering form fitting the counterbore of the leader pin and adapted to efiect a slight expansion of the same, and a companion set member having sliding engagement with said leader pin.

3. In a die set for unching and forming presses the combination of a set member formed with a cylindrical orifice, a leader pin cylindrical throughout to accurately fit being slitted radially, a conical plug of complementary tapering form fitting the counterbore of the leader pin and adapted to effect a slight expansion of the same, a

companion set member having sliding engagement with said leader pin, and a lubricant carrier arranged in the central bore of the leader pin and the leader pin having a peripheral groove and a passage connecting said groove with said bore. M

4. A leader pin for die sets of punching and forming presses, comprising a body portion cylindrical throughout formed with a central bore, extending the entire length of the pin, one end of said. bore being formed with a conical counterbore of a minute taper, said pin end being slitted radially, and a conical plug of a complementary tapering form fitting the counterbore of the leader pin and adapted to efiect a slight expansion of the attaching end of said in.

Signed at Chicago, Illinois, this 1st day of May, 1924.

ROBERT C. DANLY. 

